Your cart is empty

from the blog

Shark Bytes

August 2014 Shark Bytes

written by Monique Fallows

Posted on Monday, 1 September 2014

Dear Shark Lovers,

I am very happy to report that we have managed to survive through August and as of right now we still have a number of Great White Sharks present at Seal Island. This is great news as I really thought there was a chance whilst writing July’s Shark Bytes that we would have reached the end of the season at this point! In this report I will be talking about the up and down activity of the predatory events, how weather has played a part in our sightings and of course observations of who exactly, in terms of sharks, has been around this month.

Predation Activity

Historically over the last 18 years the middle of July to about the 10 of August has always been the time period where we record and observe the most intense amount of predatory events. I have already reported in July that the activity had fallen well short of what we normally see.

As we went into the early part of August activity remained low with sometimes no events at all to perhaps a handful each day.

We did have the chance to watch and photograph one particularly spectacular event where a very large shark we estimated to be over 4 meters in length did a massive full breach through the middle of a group of seals. The seals scattered everywhere as the huge shark came bursting through and on this occasion the shark was successful. With 8 different events on this day it was our busiest day of the previous 2 weeks.

Shortly after this events slowed down again and the actual predation events starting taking on a new type of behaviour of very slow consumptions of the seals carcass on successful events.

Normally events take place very fast and the seal is eaten in a matter of moments. We think this is due to pressure from other sharks in the area making it a realistic possibility of the successful shark losing its kill to another shark. You can appreciate that the splashing and noise from the chase will attract other sharks to the area and there is no way a shark would want to risk losing its meal. Also remember that in terms of shark hierarchy the bigger sharks dominate, and smaller sharks can easily lose their kill just by larger sharks using their muscle so to speak.

Over about a week to a 10 day period we observed sharks taking a long time to consume their kills, sometimes for up to 5 minutes long. It always fascinates me how aware the sharks are of energy conservation. A slow, laborious feed will take far less energy than a rather violent and thrust-filled consumption. When there are far fewer sharks around, and the threat of losing a kill is far less, there is no need for a shark to use the same energy compared to a pressure situation. This also shows that the sharks are very well aware of how many sharks are currently in the area, and possibly which actual sharks are present too.

So, although we were not seeing high amounts of predation it was still very interesting for ourselves and our guests to observe this kind of feeding behaviour, and of course it was a great chance to watch a shark feed and get a really great look at that individual.

This slow consumption has definitely been an indicator over the years that the season at Seal Island is starting to slow down as the sharks move into other feeding areas such as the inshore waters of False Bay and up the coast.

We were also struggling somewhat to observe sharks around the boat. We did have a complete miss on one trip but the average was 1 to 3 sharks per trip. So, you can appreciate that our thoughts were definitely that the end was imminent!

How Weather Affects Activity

However, Seal Island still had a few tricks up her sleeve and just after the middle of August we had one very good morning of 10 predatory events and 6 sharks at the boat. This morning was just preceding a fairly big low pressure system (ie bad weather) and we certainly know from our data collected over the years that low pressure systems do definitely stimulate the sharks to hunt. This may be due to the higher numbers of seals returning to Seal Island to shelter from the weather (which equate to more hunting opportunities) as well as sea and climate conditions that serve to aid the sharks in being more successful.

In the week after this we witnessed events on all mornings. This coincided with our annual Great White Trail Expedition so we were thrilled that the expedition members got to experience the natural predation activity that makes Seal Island so famous. The Great White Trail is a trip designed to take in all 3 Great white shark locations in South Africa. Starting in False Bay the focus is to view natural predatory events and then moving along to Mossel Bay and Gansbaai this time of the year provides excellent cage diving opportunities.

At Seal Island we saw hunting events in various degrees of spectacular-ness (is that even a word?) but we also had good sightings of sharks around the boat. On our last day we had an extremely obliging and relaxed male that stayed with us for most of the morning. The weather was perfect and the flat, glassy sea made the encounter with this shark very special. The predation events are always a highlight to see but for me nothing beats a perfect day with a slow, relaxed shark gently cruising around the boat…. That is when one really connects with this amazing animal!

The whole Great White Trail group was made up of some serious shark and nature lovers so it was fantastic to be able to share this with them. Although weather did not allow them to get out in Gansbaai the 3 days in Mossel Bay was very successful with high shark numbers around the boat. We already can’t wait for the 2015 Expedition!

And Another Cold Front Hits...

Shortly after the Great White Trail we had another approaching low pressure system headed for Cape Town with big wind and swell forecast. This was at the start of our Scientific Focus Expedition with Dr Alessandro da Maddalena which focuses on the experience at sea and lectures on Shark biology in the afternoons.

Seal Island is truly a magical place and is always full of surprises… it is almost like she is her own beast and we can never control her. True to form at the very end of August when we thought the season was all but over Seal Island produced the highest predatory activity days of the season!

The cold front that hit must have produced the perfect hunting conditions for the sharks and they arrived in full force. Over a period of 3 days we recorded 44 events and many of they were very spectacular and which we got to see very close to us.

I know that this number is not what we would consider high compared to other seasons, but this season it has been the peak of activity, with many long and lunge-filled chases and spectacular high breaches.

On the third day we went out in very poor conditions as we know that these conditions can be very good for natural predation. The wind was up to 30 knots and it was pouring with rain, in a strange way these were spectacularly beautiful conditions! It was definitely our morning and we were close to a number of events. I was lucky enough to see a completely full white belly breach with a seal bouncing off the sharks snout by just looking in the right place at the right time… definitely the most impressive sight I have seen this season. I can close my eyes and still see it…

Some Interesting Individual Shark Observations

Whenever possible we try to identify the individual sharks at each predation event or at the very least get a size estimate.

“Shy Guy” was seen making two kills in one morning which means we recorded him at Seal Island during June, July and August.

The feisty shark we call “Pinkie” has still been coming up to the boat and we have also seen him hunting on at least one occasion. In true Pinkie fashion it was a crazy predation where he breached 3 times and managed to catch the seal.

Pinkie, along with “Canon” has now been at the Island since mid-July so it is a long period of time now for them to be hanging around. All three of these sharks are males and although there has been a very high turnover of other sharks identified I would say 90% of them have been males. We don’t normally see such a definite sexual segregation at Seal Island so this is interesting for us.

When I mention that we have had a high turnover of sharks I mean that day to day we are seeing different sharks and generally sharks that we do not recognise.

We have also recorded bigger than average sharks at predatory events and many of them in the 3.8m to 4m size range. At one particular event we estimated the shark to be over 4.5 meters, one of the biggest sharks we have recorded this year. We only got a true idea of this shark’s size when Chris & I looked at the photographs of the event. Even though the seal is in front of the shark’s dorsal fin you do not lose the perspective of how truly huge this animal is. The dorsal fin is massive and completely covered in copepods (parasites) and this is definitely not a shark we have seen up at the boat.

In conclusion there are many sharks we are recording at predatory events that are very large animals and that are not coming up to the boat. It definitely has been a very thought provoking season…

Cetacean Sightings

We have had scattered sightings of small groups of Common dolphin during August and normally on days when the wind has been blowing from the South Easterly direction.

August is also at the start of the Southern Right Whales season and we had our first sightings of these whales as they migrate from Antarctica to our South African coastline right from the start of the month.

They were present in high numbers right up to the middle of August until the South African Navy unbelievably held a night shooting exercise in False Bay. Immediately following this the whales disappeared and only in the last few days have a few individuals been seen again.

It is astounding to me that the Navy firstly doesn’t seem to worry about the wildlife they are disturbing in the Bay and secondly that they are even allowed to undertake exercises such as this when it is peak season for the threatened Southern Right Whales in False Bay. It really has been very upsetting.

Chris and the WASP

Many of you would have seen (and hopefully enjoyed!) “Air Jaws: Fin of Fury” during Discovery Channel’s Shark Week a few weeks ago. If you did, you would have had a chance to see Chris’s experience in the WASP whilst we were in New Zealand filming the Great white sharks off Stewart Island.

Chris and I will away for the next 10 days but Poenas and our Team will running trips as per normal. I am not sure if the sharks will still be here upon our return but I will for sure keep you all updated come the end of September.